The proposed studies examine how children acquire counterintuitive concepts - how they learn and come to believe in ideas that defy their intuitions about how the world works. Being able to sort through and selectively accept certain counterintuitive information has profound implications for children's acquisition of a host of culturally-transmitted ideas, ranging from the scientific to the spiritual, including ideas relevant to children's health. For example, children who are first learning about biological evolution must override their idea that species do not change across generations, and for children to understand heliocentrism, they must override their first-hand perceptions (every day, the sun appears to revolve around the earth). Moreover, for children to understand the importance of bacteria and viruses, they must believe that powerful entities exist that cannot be perceived with the naked eye. Thus, counterintuitive concepts play pivotal roles in many domains of thought. Though recent research has examined how children represent counterintuitive concepts, and how much children trust information that others provide, these two lines of research have yet to be merged. The proposed experimental studies are designed to address three specific aims with regard to how children come to believe counterintuitive concepts: Aim 1: Assess how various aspects of the context--including the immediate learning context and the broader cultural context--influence children's willingness to accept counterintuitive ideas. Aim 2: Determine what types of people children trust when learning counterintuitive information; in particular, examine whether and when children consider informants' traits and their expertise Aim 3: Identify qualities of the information itself (e.g., explanatory depth) that affect children's willingness to accept the counterintuitive information as true. To address these aims, children (4- to 8-year-olds) attending schools and museums in the Boston area will engage in tasks in which they learn counterintuitive information from different types of people and in different contexts. Results promise to contribute both to basic science and to children's formal and informal education. Results will inform and inspire research on science education in both formal settings (i.e., the classroom) and informal settings (e.g., science museums and educational media). Results will also inform research on the transmission, pervasiveness, and development of counterintuitive concepts embedded in children's spiritual and religious beliefs - beliefs that can contribute to a sense of meaning and mental well- being. Moreover, these results have implications for children's physical health - understanding how best to convey counterintuitive ideas to children, educators and parents can better teach children about important health-related entities, such as bacteria and viruses. Intervention studies can then capitalize upon the factors that are identified as best promoting children's acquisition and acceptance of counterintuitive concepts.